v/vlib/encoding/xml

Description

xml is a module to parse XML documents into a tree structure. It also supports validation of XML documents against a DTD.

Note that this is not a streaming XML parser. It reads the entire document into memory and then parses it. This is not a problem for small documents, but it might be a problem for extremely large documents (several hundred megabytes or more).

The public function parse_single_node can be used to parse a single node from an implementation of io.Reader, which can help parse large XML documents on an element-by-element basis. Sample usage is provided in the parser_test.v file.

Usage

Parsing XML Files

There are three different ways to parse an XML Document:

1. Pass the entire XML document as a string to XMLDocument.from_string.
2. Specify a file path to XMLDocument.from_file.
3. Use a source that implements io.Reader and pass it to XMLDocument.from_reader.

import encoding.xml

//...
doc := xml.XMLDocument.from_file('test/sample.xml')!

Validating XML Documents

Simply call validate on the parsed XML document.

Querying

Check the get_element... methods defined on the XMLDocument struct.

Escaping and Un-escaping XML Entities

When the validate method is called, the XML document is parsed and all text nodes are un-escaped. This means that the text nodes will contain the actual text and not the escaped version of the text.

When the XML document is serialized (using str or pretty_str), all text nodes are escaped.

The escaping and un-escaping can also be done manually using the escape_text and unescape_text methods.